Canon has stopped supporting the Canon 5D (classic) and has no plans to make a driver for 64-bit Windows 7. Will FPV Pro allow me to shoot with my 5D tethered within Lightroom 3? I urgently need to buy a new computer and it seems all the new PC laptops have only Windows 7 64-bit OS now. Thanks for your help, in advance.

The short answer about FPV Pro is no: the 5D cannot be tethered without Canon software, but there is hope: you can try running the Canon EOS Utility under Windows XP Mode, a virtual machine running 32-bit Windows XP within Windows 7 x64. The EOS Utility can be set to transfer files to a folder on your computer, and FPV Pro x64 can be used to monitor this folder using it's built-in tracking mode (T). If you can get the Canon EOS Utility to work under XP Mode then thethering will certainly work well.

You need to check with Adobe to find out if Lightroom 3 supports your camera, and on which platform.